CDOM Monitoring (CDOM-Station, CDOM-Station Pro)

Chelsea Technologies Group's CDOM-Station and CDOM-Station Pro systems allow utility operation managers, process scientists and engineers to assess real-time levels of coloured dissolved organic matter (CDOM) in water systems. This is achieved by detecting UV CDOM fluorescence, which has been shown to correlate with organic levels in a wide variety of water environments, providing significantly enhanced improvements in sensitivity over conventional absorbance methods.

The CDOM-Station comprises a CTG UviLux fluorometer and a Watchkeeper wall mounted data display and logger. CTG’s UviLux fluorometers detect UV fluorescence with industry-leading sensitivity and selectivity and have been optimised for minimal interference from water turbidity.

Data is displayed on the Watchkeeper’s colour touchscreen and is logged internally. Up to three 4 - 20mA outputs are provided for data transmission.

Introduction

CTG’s CDOM-Station and CDOM-Station Pro systems allow utility operation managers, process scientists and engineers to assess real-time levels of coloured dissolved organic matter (CDOM) in water systems. This is achieved by detecting UV CDOM fluorescence, which has been shown to correlate with organic levels in a wide variety of water environments, providing significantly enhanced improvements in sensitivity over conventional absorbance methods. The CDOM-Station comprises a CTG UviLux fluorometer and a Watchkeeper wall mounted data display and logger. CTG’s UviLux fluorometers detect UV fluorescence with industry-leading sensitivity and selectivity and have been optimised for minimal interference from water turbidity. Data is displayed on the Watchkeeper’s colour touchscreen and is logged internally. Up to three 4 - 20mA outputs are provided for data transmission.

What is the difference between the CDOM-Station & CDOM-Station Pro

The CDOM-Station comprises a single CTG UviLux CDOM fluorometer and a Watchkeeper wall mounted data display and logger.

How does it work?

CTG’s CDOM-Station and CDOM-Station Pro detect UV fluorescence from Dissolved Organic Matter (DOM). These compounds absorb UV light and re-emit a fraction of this energy as fluorescence at longer wavelengths. Fluorescence intensity is directly proportional to concentration. The technique is widely recognised as one of the most sensitive detection methods available. CDOM may originate from terrestrial or riverine sources and fluoresces in the blue region when excited with UV light. Only aromatic ring compounds can be detected by fluorescence, with emission wavelengths generally increasing with the size of the ring compounds. CTG excite at short UV wavelengths enabling highly sensitive detection of aromatic compounds.

Configuration

The CDOM-Station and CDOM- Station Pro have been designed for both indoor and outdoor operation, with the UviLux fluorometers either fitted within a water trough or mounted in flow-through manifolds for in-line operation. A single cable connects the UviLux fluorometers to the Watchkeeper display and logger unit, which is powered from a 24 Vdc supply. Signal inputs are presented on the screen and up to three 4 – 20 mA signals can be accessed for data system networking. Audible alarms or control valves can be fitted and programmed to alert or activate when signals exceed user-set thresholds. Data is recorded onto a 2 Gbyte memory card. Data can be download via a USB cable, or by removal of the memory card.

Specification

UviLux Fluoremeter

Size

Ø70 x 150 mm

Weight

800 g

Pressure rating

60 bar

UviLux Performance

CDOM

Tryptophan

Sensitivity (QSU)

0.01

0.01

Calibrated range (QSU)

600

600

Example compound: sensitivity – range (ppb)

PTSA* 0.02-900

Tryptophan 0.02-1200

*PTSA pyrene tetrasulphonic acid

CDOM-Station, single UviLux fluorometer with Flow Manifold

Size

Ø130 x 20 0 mm

Weight

2.5 kg

Fluid connections

Union, 20 mm, PN16

Perssure rating

4 bar

Max operating temp.

55 ºC

CDOM-Station Pro, two UviLux fluorometers with Flow Manifolds

Size

265 x 200 x 200 mm

Weight

5 kg

Fluid connections

Union, 20 mm, PN16

Pressure rating

4 bar

Max operating temp.

55 ºC

Watchkeeper display and logger

Display

320 x 240 pixel qVGA backlit LCD

Display Size

70 x 50 mm

Size

200 x 110 x 60 mm

Weight

900 g

Memory capacity

2 Gbyte

IP Rating

IP67

Voltage input

24 Vdc

Power

2.8 W @ 24 Vdc4.6 W @ 24 Vdc (Pro)

Temperature range

-20 ºC to 55 ºC

In view of our continual improvement, the designs and specifications of our products may vary from those described